Machine tool



aieniecl drug.. 22,. i939 reise RIACHINE TOGL Horace A. Osborne, Racine,Wis., assigner of twoffths to Webster Electric Company, Racine, Wis., acorporation'of Wisconsin Application september 24, 1937, serial No.165,442

5 Claims.

The present invention relates to machine tools. and is particularlyconcerned with a bushing retainer attachment adapted to be used withmachine tools, such as drills, reamers, or the like for supporting abushing or bushings Where one or more operations are to be performedthrough the same orifice in a machine, jig, fixture, or attachment,

- One of the objects of the invention is the provision of an improvedmachineA tool arrangement which is adapted to eliminate the use of loosebushings which are objectionable both on account of the slowness ofoperation and the l5 ease with which such bushings may be mislaid orlost.

Another object is the provision of an improved bushing retainerstructure by means of which a bushing of the correct size and dimensionis movably supported in relation to a drill or other a machine tool insuch manner that the bushing can be used for aligning the tool inthecorrect operating position.

Another object of the invention is the provision of an improved bushingretaining structure of the class described in which the bushings may bevery quickly changed and in which the tools may also be quickly changed.

Another object is the provision of an improvedguide bushing arrangementin which the guide bushing ceases to revolve during the time it isperforming its guiding function, and also in which the guide bushingrevolves'with the tool at all other times so as to prevent Wear on thebushing structure.

Another object is the provision of a bushing retaining structure-Whichis adapted to .take care of various lengths of standard tools and thevarious types of Shanks.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawing, in which similarcharacters of reference indicate similar parts throughout the severalviews.

Referring to the single sheet oi drawings- Fig. 1 is a verticalsectional view taken on a plane passing through the axis of the tool,with the tool in elevation; n

Fig. 2 is a transverse section taken on a plane at right angles to theaxis of the tool, the plane being shown by the lines 2--2 of Fig. 1;

Fig. 3 is a View showing another form of tool driver; f

Fig. 4 is another modification of the tool driver; and

Fig. 5 is another modification.

Referring to Fig. '1, I0 indicates in its entirety a work piece in whicha cylindrical bore II- is to be made, andy I2 indicates a part of thejig ywhich holds the work piece IIJ in proper position underneath thedrill bit I3. The member I2 may (Cl. 77-55l 'ce the upper or clampingplate of the jig holding the work piece I0, and it may be provided witha bore I having a guide sleeve I5 mounted in said bore, and providedwitha radially extending shoulder I6 engaging the top of the platel2.

The guide sleeve I5 has a cylindrical bore I'I which is adapted toslidably receive the bushing I8. The bushing I8 comprises a metal memberof substantially cylindrical shape adapted, to have a sliding fit inthebore il and provided with a centrally'located bore 2G which is adaptedto slidably and rotatably receive the drill bit`l3.

The bushing i8 has a. radially-extending ange 2 I, the lower iiatsurface 22 of which engages the top of the Aguide l5. The outer edge ofthis flange 2| has a cylindrical surface 23 which is adapted to fit in acounterbore 24 in a tubular housing 25. The tubular housing 25 hasfacylindrical bore 26 extending through it, the bore 26 being separatedfrom the bore 24 by an annular shoulder 21 against which the flange 2|is seated.

On the side of the ange 2| opposite to the shoulder 21 the tubularhousing 25 is provided with a groove 28 adapted to receive a split ring29 which is similar to the ring 30 in the groove 3I, used at the otherend of the housing 25. The structure of one of these rings may be seenin Fig. 2, where it will be observed that it is a ring of round wirebent to substantially circular form and having its ends 32 spaced fromeach other suiliciently so that the ring may be sprung in ward to get itout of the groove 28 or 3l.

The split rings have an initial outward tension which causes them tospring into the grooves. The bushing 2I is thus ixedly secured in thehousing 25, but may be very quickly removed by removing the ring 29. Thebushing I8 is also preferably provided with an upwardly projectingcylindrical lug 33 on its upper side, about which the spring 34 may belocated so that the spring is kept in alignment with the bushing and outof contact with the housing 25.

The spring 34 consists of a helical wire spring which is under some`tension even when the spring is fully expanded in the housing 25. Theposition shown in Fig. 1 is that in which the spring 34 is partiallycontracted and the drill'bit I3 is ready' to enter the bore II or hasjust been removed from the bore.

The upper end of the housing 25 .is preferably provided with a pluralityof additional grooves.

36 for receiving the split wire ring- 3B, in the eventit is desired touse the bushing retainer attachment with shorter drills. The drills. maybe of various lengths, andas a long drill is Iused and resharpened itgradually decreases in length,

ment to be adapted in length to the drill bit.

The housing 25 also slidably supports a retain-.

" and these additional grooves permit the attach-V having an outercylindrical surface 38 adapted to be slidably mounted in the bore 26 ofhousing 25.

'I'he retaining ring 31 is provided with an inwardly extending annularflange 39 which serves two purposes. The lower face 40 of the iiangeserves as a seatl for the upper end of the spring 34. The'lower skirt4l' of the retaining ring 31 serves ,to maintain thealignment ofthespring 34 which the skirt 4| is adapted to receive.

The other purposefor the flange 39 is to provide an annular shoulder 43for supporting the outer race 44 of a ball bearing. The race 44 isprovided withl the`usual inner groove of half circular cross section forreceiving the balls 45, and` the balls engage innerv race 46, which islikewise provided on its periphery with a suitable groove of the sameshape.

The retaining ring 31 likewise has a groove 41 for receiving the splitring 48, which'engages the upper face of the outer race 44 of the ballbearing.

the spring 34, its upper limit of movement being determined by thelocation of the split wire ring 30, which may be in the groove 3I or anyof the grooves 36.

The inner race 46 of the ball bearing is carried In Fig. 5 isillustrated a drive shaft 55 having a socket 56 suitable for receiving aMorse Standard Shank No. 2. -The outer cylindrical surface 51 of all ofthe drive shafts 49, 60,52, 55 is substantially the same, so nthat theywill all fit in the bore 62 of the adapter 58.

Each of theo drive shafts or drill drivers mentioned also has an uppershank portion 59 which is adapted to fit in a suitable socket or chuckof a drill press. It should be understood that in addition to the drilldrivers or shafts shown, any other drill size or drive may be used, suchas, for' example, a Glenzer drive, and others.

The adapter 58 comprises a substantially cylindrical metal 'body whichis adapted to be received in the tubular housing 25, with a clearancebetween its outer cylindrical surface 60 and the inside of any of thesplit wire rings 30.- 'Ihe adapter has a centrally located bore 62, andmay be `provided with an upper counterbore 6I, to fit' the spindle 1|)of a drill press or other machine. 'I'he bore 62 is adapted to receiveany of the various drill drivers. pass through the wall of the adapter',and is adapted to engage the spindle of any of the drill drivers,flxedly securing the spindle with respect `to the adapter. The bore 62has a suitable clearance around surface 51. The spindle 10 may be,

regarded as a hollow drive shaft.

At its lower end the adapter may be provided with a tapered portion 64so as to reduce its size gradually so that it can be received inside ofthe retaining ring. The adapter has an annular shoulder 65 which engagesthe upper face of the inner ball bearing race. It also has a reduced Theretaining ring 31 is urged upwardly by The shank is held in place by theset 2,176,211 ing ring 31 which consists of a tubular member cylindrical'surface 66 for receiving vthe inner 'ball bearing race and a reducedthreaded portion 61 for receiving an annular nut 68.

The annular nut, when threaded on the re- I duced threaded portionV 61,engages the lower face of the race 46 and clamps'it to the adapter.

There is a clearance between the nut 68 and all parts of the retainingring 31 and a clearance between all -parts of the 4adapter 58 and the ohousing 25 or the retaining ring 31.

Thus the adapter 58 is so arranged that it 'rotates freely with respectto the housing 25 by means of the ball bearing. The ball bearing may beof relatively light structure. such asV is usually termed an airplaneball bearing and the friction of the ball bearing is such that whenthere is nothing engaging the bushing 2| the friction of the ballbearing and .perhaps that of the` drill bit in the guide bore I1 causesthe housing 25 to rotate with the drill bit and adapter.

Thus all wear on the ball bearing is avoided exceptwhen the drill isactually doing work.

The machine tool is illustrated in such position as it would assume whenused with a drill press. It should be understood, however, that it lmayalso be usedl wherev the part upon whichthe operation to be performed issubjectedl to rotation,

and the cutting or'operation tool held stationary.

This might take place, for example, in a lathe.A

Theoperation of the presentI machine tool attachment is as follows: ITheshank 49 is se-A cured in the chuck or socket of a drill press, and

subjected to rotation. The entire mechanism is lowered by means of theusual handle on a'drill press, and at -this time the complete housingand mechanism is in rotation. Uponcontact of the bushing 2|4 withtheliner bushing I5, the guide bushing `2| ceases to revolve, and thecutting tool or drill I3 continues to revolve in the guide bushing.

When theface 22 engages the upper surface of .the liner bushing I 5, thedownward motion of the housing 25 ceases, and Athereafter the adapter,

drive shaft, .and drill move downward, the retaining ring 31lslidir'iggdo'wnward in the housing 2 5. 'Ihe cutting or operatingtool'continues to advance through the guide bushing I5, while thebalance of the mechanism, comprising the bushing 2| and housing 25, is`at rest.

This compresses the spring 34, and'this motioncontinues until the drillI3 has 'performed its work upon the workpiece |0, such as, for example,making the bore II. Upon the lifting of the handle of the' drill press,the drill I3 is withdrawn, and the'sprlng 34 expands, moving theretainerring 31 upward until ithits the split ringv 30. The tool is now readyAfor another operation, or a second cycle.l

If the next operation is to be performed on another spindle or machine;.where it is stillnecessary to guide the tool, another of these'attachments may be used with a guide bushing of the same or differentdimensions on the inner diameter, but having the same outer diametertocontact the llnerbushing.

Should the succeeding operation not require a guide bushing, no furtherattachment would be necessary, and the drill may be used with theattachment onv it, Just as though the 'attachment were not present.'I'he liner bushing may be of suilicient size to admit the use of a tap,counterbore, or other tool of larger dimension than the original cuttingor .operating tool', such as the with cutting tools oi even largerdiameter.' A number of holes of different sizes may be bored by the useof a number of these attachments, and the drill may be suitably guidedby the jig in each case.

The series of grooves which is provided at one end 'oi'.thehousingpermits theadjustmnet of the device to compensate for wear of the tool,or to accommodate various lengths of standardr tools.

The split rings are vvery quickly removed, and l new bushings may bevery quickly assembled with the housing. The whole device may bedismantled by merely removing two split rings andorre nut. Whenvchanging or sharpening tools, it ,is only necessary to release the setscrew 63 in the adapter which holds the. adapter to the spindle of thedrill press or other machine, and thereafter the drill and driveshaitmay be removed.v In order to change the guide bushings 2i, it isonly necessary to remove the split 'ring 29 at the bottom of the housingand insert a new bushing, land then permitthe split ring to spring backinto place.

In some embodiments of the invention, parts 49 and I3 may be replaced bya single drill bit or` other tool of suiiicient length.

When the cutting tool is at rest, and out of operation, vtheentire-mechanism revolves with it, thereby reducing wear on the ballbearing, and y also preventing excessive wear on the guide bushing or`other parts rof the mechanism.

, It should be understood that the present attachment may be used withvarious types oi operating tools other than drills, and I do not wish tobe limited to the speciiic example which has Y been selected toillustrate the invention.

While I have illustratedv a preferred embodiment of my invention, manymodications may` be made without departing from thesp'irit of the.

go invention, and I do not'wish to be limited to the precise details ofconstruction set forth, but desire to avail myself 4of all changeswithin the scope of the appended claims.

Having thusxdescrbed my invention, what nI as new and desire to secureby Letters Pat' ent of the United States, isfv 1. In a machinel toolattachment, the combination of a tubular metal housing, said metalhousing having a guide member removably secured in onel end and providedwith an aperture for guiding a drill or the like, with a sliding membermounted in said tubular metal housing. stop means at the end oi' saidtubular metal housing for limiting the outer movement of said` slidingmem- '35 ber, spring means between'said 'sliding member and said guidemember, an anti-friction bearing carried by said sliding member, and atool-holder 'can'ied by said sliding' member whereby the drill or thelike may b e 'rotated and reciprocated iny a said guide member and saidlguide member may' .be carried/by said tool from one work piece toanother.

2. In a machine tool attachment, the lnatien of a' tubular metalhousing, said metal u housing'having a guide member removably secured inone` end and provided with an aperture for guiding a drill or the like,with a sliding member mounted in'said tubularnjetal housing, stop meansat the end of said tubular metal housing for limiting the outer movementof said sliding member, spring means between said sliding member andsaid guide member, an v:vinti-friction bearing carried by said, slidingmember, 'and' atool cured in one end and provided with an apertureGombidrillgor the like may be rotated and reciprocated in said'guidemember and said guide member may be carried by said tool from one workpiece to another, said stop means comprising a substantially circularresilient spring member adapted to be received in a groove in saidtubular member and projecting from said groove to engage. said slidingmember.

3. In a machine tool attachment the combination of -a 'tubular metalhousing, said metalv housing having a guide ,member removably securedinfonerend and provided with an aperture for guiding a drill or thelike, with a' sliding member mounted in said tubular metal housing,

stop means at the end of'said tubular metal hous- `ing for limiting theouter movement of said sliding member, spring means between said slid'ing member and said guide member, an antifriction bearing carried bysaid sliding member, and a tool holder carried by said sliding inem-Vspring member adapted to bereceived in a groove in said tubular memberand projecting from said grove to 'engage said sliding member, saidtubular member having a plurality of similar grooves for the purpose ofadjustably locating said stop member.

4. In a machine toolattachment, the combination of a` tubular metalhousing, said metal housing havingva' guide member' removably seforguiding a drill or the like, with a. sliding member mounted in saidtubular metal housing. stop means at the end of said tubular metal-husing forlimiti'ng the uter movement oi said sliding member, springmeans between said slidlng member andisaidguide member, an antiber, anda'. tool holder carried by said sliding `member wherebythe drill or thelike may be rotated' and reciprocated in .said guide member and saidguide member may bev carried by said tool from one work piece toanother, said guide vsaid ltubular member and engaging the outer surfaceof said guide member.

5. In a machine tool attachment, the combi- 20 lber whereby the drill orthe like may be rotated Afriction bearing carried bysaid sliding memxnation of a tubular metal housing, said metal housing having a guidemember removably lsecured in one end and provided with an apertureyfor`guiding a drilL` or the like, with a sliding member mounted in saidtubular .metal housing, ,stop means at the end of said tubular metalhousing ior limiting the outer movement oi? said.

sliding member, spring means between said sliding member and said guidevmember, an antifriction bearing carried by said sliding member, and atool holder carried by said sliding member whereby the drill or the likemay be rotated and reciprocatedl in said 'guide -mernberand lsaid.

guide member may be carried by said tool fromone work piece to another,saldi sliding memberv being formed with/,an annularseatand are-ltaining, ilange, and said guide member' being iormegbwith an alignmentlug forsupporting of saidspring in spaced, relation tol l both endsHons'cnlafosnoaun.:

